As illustrated in Japanese Unexamined Patent Application Publication 2002-71473, there is a fluorescent temperature sensor of this type provided with a fluorescent material, a light projecting element for projecting light at the fluorescent material, a light receiving element for receiving light from the fluorescent material, an optical branching device (a half mirror), and a calculating/controlling unit.
In this fluorescent temperature sensor, light from the light projecting element passes through the optical branching device to be projected at the fluorescent material. The light from the fluorescent material that is optically stimulated thereby is reflected by the light branching device to a light receiving element side. The temperature of the temperature measurement environment wherein the fluorescent material exists is calculated and outputted by the calculating/controlling unit based on the changes in the optical flux (the brightness) from the fluorescent material, detected by the light receiving element, or in other words, based on the attenuation characteristics of the fluorescent light.
Here the individual components such as the light projecting element, the fluorescent material, and the light receiving element, and the module that is structured including these components, will degrade it over time due to use, and the functionality thereof will eventually come to an end.
However, in the conventional fluorescent temperature sensor, when there is a failure due to the degradation of the individual elements, or the like, the identification of the location of the failure is difficult. That is, it is necessary to disassemble the sensor and check the operation of several different modules and components individually in order to identify the location of the failure, and thus there is a problem in that the identification of the location of a failure is laborious and time-consuming.
In contemplation of the situation set forth above, the object of the present invention is to provide a fluorescent temperature sensor wherein a the location of a failure can be identified easily.